OF THE FOSSIL PLANTS OF THE COAL-MEASURES. 
263 
young ones. On the other hand, the structure of their testse shows them to be true 
seeds and not ovules. Unfortunately the nucleus has almost always disappeared ; and 
where traces do remain we have as yet seen nothing beyond a cellular perisperm. 
Further research may, however, reveal other examples in which traces of the peculiar 
and characteristic endosperms of the Conifers and Cycads may be detected. It is very 
desirable that all who are in a position favourable to the prosecution of such researches 
should keep this important possibility steadily in view. 
Whilst thus avoiding all attempts definitely to associate these seeds with individual 
plants, we must not overlook the fact that most of them have been obtained either from 
the thin upper foot coal-seam of the Ganister beds, from which so many of the finest of 
our Oldham plants have been derived, and that, consequently, we naturally look to 
those plants to furnish the parent stems on which these seeds grew. But they fail 
to show any structures with w'hich the seeds can reasonably be associated. The only 
stems which we yet possess that can with any degree of probability be identified with 
the seeds are the Dadoxylons. Brongniart thinks that the Noegg err athice may have been 
the parents of some of them, especially of Cardiocarjpon ; but unless the Cordaites were 
Nceggerratliice we find no trace of that group in the Oldham nodules ; and, as already 
remarked, our chief specimens of Dadoxylon have been derived from the marine beds of 
the Ganister series and of Coalbrookdale, into which they had obviously been drifted, 
and in which the seeds are extremely rare. 
Index to Plates 5-16. 
Bachiopteris corrugata. 
Fig. 1. Small portion of the external surface of the cortex, with its transverse ridges 
and furrows. Enlarged 7-| diameters. 
Fig. 2. Transverse section of the lower extremity of the fragment of a stem. Enlarged 
1-| diameter. 
Figs. 3 to 12. Series of similar sections to fig. 2, arranged numerically in their ascending 
order. Fig. 4 is enlarged 3 diameters, the remainder 1^- diameter. 
The letters of reference throughout this series indicate the following 
structures : — 
a. Medulla, b. Axial vascular cylinder, c. Primary vascular bundles 
given off from the axial cylinder, probably to petioles, d. Secondary vascular 
bundles given off either from the primary bundles (c) or from the axial 
cylinder, e. Inner cortical tissue, f. Outer cortical tissue, g. A branch 
or petiole separating from the main stem and enclosing a primary vascular 
2 o 2 
